1. Field of the Invention
The present invention relates to steel planks for scaffolding and, more particularly, is directed to a steel plank for scaffolding that has a bottom plate that is coated with a non-slip surface.
2. Description of the Invention Background
Scaffolding is used in a variety of industrial and construction settings as an elevated platform for workers and equipment. Scaffolding typically consists of planks that rest horizontally on a vertical metal frame or are lapped on top of other planks that rest on the metal frame.
The most common type of material for plank construction is wood. Wood has a high coefficient of friction and therefore the planks do not easily slip off of the metal frame or off of other planks. Wooden planks may also be nailed together to increase the stability of a scaffolding structure and to reduce slippage of the planks.
The use of wood as a material for plank construction has many disadvantages. Wooden planks are typically expensive because a high grade of wood must be used in their construction. Scaffolding is often used in harsh environments such as in oil refineries, petrochemical plants, and paper mills where chemicals such as acids come into contact with the scaffolding structure. Exposure to chemicals causes wooden planks to deteriorate and weaken, which directly affects the load-bearing capacity of the planks. Wooden planks must be inspected and tested before each use. The testing procedure is such that it may actually weaken the wooden planks. Thus, under normal usage, wooden planks typically last about 3 to 4 years until they need replaced.
Wood also has the disadvantage that it becomes slippery when wet. Thus, if wooden planks are used in applications where water is present or if they are used in adverse weather conditions, the planks may become unsafe for the workers using the scaffolding. Also, wooden planks have the disadvantage of being heavy due to their solid mass. Because of this disadvantage, transportation of wooden planks and scaffolding construction using wooden planks is burdensome.
The prior art has attempted to solve the many problems inherent in wooden planks by constructing the planks out of metal. However, metal does not have the high coefficient of friction that wood has and thus prior art metal planks do not have the non-slip safety advantage of wooden planks. The Applicant of the present invention has proposed a solution to the slippage of metal planks in U.S. Pat. No. 5,555,955, wherein a combination scaffold plank was disclosed that is comprised of a channel-shaped metal plank with slip-resistant blocks fastened to its underside. The blocks prevent the planks from slipping off of the metal frame or off of each other. The invention further discloses a board fastened to the bottom of the blocks which creates a uniform surface that runs the length of the plank. The prior invention has the advantage of the strength of a metal plank and the non-slip surface of wood. However, the prior invention has the disadvantage in that the planks are still constructed partially of wood, which is subject to deterioration, especially in harsh environments.
As such, there is a need for a steel plank for scaffolding that has a bottom plate that reinforces the steel plank and has a non-slip bottom surface which prevents slipping and enhances the safety of the steel plank when used by workers. There is also a need for a low-cost steel plank for scaffolding that will not deteriorate over time in the adverse environments in which such planks are often used.
The subject invention is directed toward an improved steel plank which overcomes, among others, the above discussed problems and provides a steel plank which has the non-slip property of wooden planks yet has the safety and durability of a steel plank.